


Into The Night

by spazhime



Category: Undertale (Video Game)
Genre: F/M
Language: English
Status: Completed
Published: 2020-09-04
Updated: 2020-09-04
Packaged: 2021-03-06 16:14:40
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,674
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26281747
Author URL: https://archiveofourown.org/users/spazhime/pseuds/spazhime
Summary: So uh. This originally was gonna be written as a joke, like. A sexy pun filled ridiculous smutty joke. but I got to writing and it kinda came out as half joking and half serious, which kinda matches sans. Lmao.Basically, the group goes out to a dance party (semi-dancetale), sans and reader get busy
Relationships: Reader/Sans, f!reader/sans, female reader/Sans
Comments: 5
Kudos: 50





	Into The Night

He's looking at you again. He, being Sans. And not in a "I want to take you swing dancing" way, but in a "I want to do the horizontal hussle with you" kind of way. At least, you believe that's the type of look he's giving you. You are unsure if it's the same for monsters as it is for humanity. Considering he does this to you and only you when the whole group goes out dancing, you hope it is. You, Undyne, Alphys, Sans, and Papyrus have all gone out to the monsters weekly dance off. As the main contestants dance on stage, many other monsters dance in the crowd, oftentimes leaving with their partners early to get some at home 'practice' in. 

You giggle at the thought, bringing Undynes attention off of her girlfriend and on to you.   
"What's so funny punk?", she gives you her sharp toothed grin. She knows about your crush on Sans and has been pushing the two of you together for weeks.  
"It's nothing really. I just find it interesting how much of a monsters life is surrounded in dance. At work, at home... In the bedroom" You raise one eyebrow as you say the last bit.  
At that, Undyne gives you the biggest shit eating grin she can muster and throws her arms around your shoulder   
"Hell YEAH we do." She glances over at Sans, who had taken up talking to Alphys while you and Undyne were talking.  
Her voice lowers into a semi-whisper. "Why don't you ask Bonedaddy over there to show you how we monsters make use of our beds?"

You blanch at the bluntness of the statement, staring at Undyne incredulously.   
"Bone daddy??? What the actual fuck Undyne" At this point you're holding back laughing at the statement, hoping Sans hasn't heard any of your exchange.   
Undyne lets out a healthy guffaw of laughter and slaps you on the back.   
"You KNOW that nerd is just as hot for you as you are for him right?"   
You shake your head at the statement, feeling insecure. "Undyne, you realize I'm human right? I doubt he would be attracted to me."  
She looks at you, or what seems to be straight through you, before looking a bit more thoughtful.   
She brings her face incredibly close to yours and before you can react, she says "Don't worry, I'll help you out." She cackles and pulls back, slapping you on the back once more and shimmy shammying her way over to the bar. 

You shake your head at your friends antics, not thinking anything of it, before you approach Sans and Alphys. Seems like Papyrus has shown up from wherever he had wandered off to. He notices you and gives you a wave  
"HUMAN! HOW ARE YOU LIKING THE PARTY? IT SEEMS BIGGER THAN LAST WEEKS"  
He pulls you into a bone-crushing hug as he asks, you laughing all the while.  
"It's fun Paps! I like that this one is centered on R&B instead of last week's pop, I don't quite know how to dance to pop" He gently sets you back down on the floor as you say this. Sans is looking over at the two of you with a content smile, enjoying the fact that you and Papyrus have gotten to be close friends over the last few months. Undyne returns with a few fizzy looking drinks, offering one to you and the other to Sans. You eye the drinks wearily and Undyne laughs   
"It's monster alcohol! It affects your soul directly instead of sitting in your stomach like human alcohol". She hands you the cup and you accept it, tentatively taking a sip. Your eyes widen as the drink immediately takes effect.  
"Wow" you say, "This is... Really odd. Human alcohol normally takes a while to affect me but this was instant."   
Sans speaks up for the first time, "heh. yeah monster alcohol is entirely magic. it doesnt go into your stomach at all, but goes directly into the soul. its not dangerous like human alcohol is or anything, it just helps ya to relax. its a mood enhancer too so whatever youre feeling can be amplified or minimized, depending on what that feeling is."   
You take another sip and can feel the effects a bit more, you giggle "Huh that's really nice actually. It's what we humans hope our alcohol will do when we drink it. It's nice!"  
Sans laughs lightly at your reaction as you chug the rest of the drink, “why dont we go to the dance floor? Im feeling tonights music” 

A blush appears brightly on your face, but you nod your head immediately, “Yeah! Let’s go Sans, I haven’t really gotten to dance with you much”.   
The two of you walk to the side of the dancefloor, as you pointedly ignore the shit eating grin Undyne is giving you. You and Sans turn to face each other, right as a particularly raunchy bump and grind song comes on. You blush harder, but with no hesitation begin to sway your hips to the beat, no doubt losing any insecure feelings from the drink you had earlier. Sans raises his brow bone with a slight blue blush, his hands gently reaching for your hips, but then only hovering over them as he begins to move to the music as well. Feeling spurred on by his actions, you raise your brow back at him and place your hands over his, and push them gently down onto your hips. His blush deepens and he makes a slightly unsure face.   
“Heh you sure that uh. monster drink you had wasnt too strong?” You giggle prettily and shake your head. “Nope” you say, emphasising the p with a loud ‘pop’. “I think it was just enough for me to loosen up” 

He smiles wider then, gently gripping your hips with a bit more enthusiasm. “‘kay. just checkin’” Your arms raise up to grip his shoulders as the both of you start dancing. It starts out just a friendly (semi dirty) dance, but quickly evolves into something a bit more. You’ve subconsciously inched towards each other, not letting go even after the next song has started up. Your chest to chest, both panting and blushing but not just from the exertion. His hands have gone up from your hips to roaming up and down your sides, feeling your curves and making you shiver. Your hips are close enough to his that they bump together and you have to hold in a groan multiple times at the friction. Sans looks to be about the same, his face scrunched up a bit, but closer to looking like pleasure than pain. He squeezes you tight and says your name quietly, “do uh. you maybe wanna go someplace else?” 

You blush, hard, but smile and nod your head. His grin becomes much wider, showing off his teeth a bit more, and you swear you see a faint blue glow from behind them, and are those canines?? Wow those are. Those are -sharp- you think to yourself. He hesitantly lets go of you, “i just gotta tell paps im turning in for the night. dont go anywhere?” the last statement turns into a question as he looks at you, seeming a little apprehensive. You feel emboldened by his actions, and you wink as you reply “Don’t worry hot stuff, I’ll be waiting”. His blush returns tenfold and he gets a dopey look on his face, and then heads off to talk to Papyrus. It doesn’t take two seconds until you are in a headlock, being noogied. There’s only one person that could be. 

“HAH! Didn’t think you had it in ya punk! You’re gonna get laaaaaaaaaaaid!!”   
You grunt at her in dismay and struggle a bit before pouting,”Undyyyyyyne shhhh everyone will hear you!” She backs away as you jokingly slap at her hands, your face as red as spaghetti sauce. Undynes face is smug as she says “I knew he was in to you. I KNEW it. Alphys and I have a betting pool with everyone as to when the two of you were gonna get together!” You didn’t think it possible but you got even more red. “UNDYNE. We aren’t even together! We’re just.. Going somewhere?” This makes her laugh and slap you roughly on the back. “Fuhuhuhu! By tomorrow I bet you two lovenerds will be together. Sans hasn’t EVER shown interest in anyone like this!” You take a quick breath in, realizing you and Sans might be on the same page. Sure you’d had a tryst here and there, but none of it was ever serious. You weren’t even sure Sans was serious about this. You didn’t know how monsters felt about one night stands, even with friends. Just before you can reply, a very smug looking Sans returns to your side. 

“hey ‘dyne”, he waves as he says this. Undynes grin gets ever wider, showing off her incredibly sharp teeth. “Hey Sans! Gonna go dance with Alph for a bit, take good care of our friend here”. She winks and walks over to where Alphys is, says something, and both her and Alphys look over while giggling. You roll your eyes and grab Sans’ hand without realizing it. He jumps slightly, startled by the sudden contact, but then tightens his grip. “c’mon then, I know a shortcut”. You blink, and suddenly you’re in an apartment. His hands slide across your waist and he pulls you close, whispering “you okay with this?” You nod your head vehemently and lean forward, you’re eye to eye with him. He smirks and starts to lean forward as well. As he does so, multiple things cross your mind. How do skeletons kiss without lips?? Is it just going to be teeth? Oh god this is going to be so awkward what if he doesn’t even have a tongue..

And suddenly, your thoughts are put to rest as you feel the softness of lips gently touching yours. You peek down, but you don’t see anything. There’s space between your lips and his teeth, but you feel resistance. Chalking it up to magic, you push close to him and he groans, sliding his hands further down your waist. They’re getting tantalizingly close to your ass now and you’re about to tell him to move them lower, when you feel a tongue tentatively touch your lips, asking permission. Normally you would hesitate a bit but the monster drink coursing through your veins (soul?) is giving you some courage. You open your mouth readily and he slides his tongue against yours. Both of you groan at the same time at the contact, and his hands finally make their way down to squeeze your ass.

This makes you groan even louder, and getting caught up in the moment you move one leg up to rest on his hip bone. His invisi-lips move from your mouth, down your jaw, to your neck. Your breath hitches as he licks right on your pulse. You can’t help but think ‘Oh god please bite me’. He’s not a mind reader however, and goes back to kissing up the side of your neck. His hands roam your thighs, getting tantalizingly close to your center without actually touching it before pulling back to your legs. You realize you aren’t contributing much, so you start roving your hands over his chest, to his back, and a bit down. His breathing gets much heavier as your hands run from his back to the front of his ribs, and he stops his ministrations on your neck to groan out the word “bed?” You vehemently nod your head and with no hesitation he hikes your other leg onto his corresponding hip. You startle and on reflex your hands grip to balance yourself. They just so happened to be on Sans’ ribs, causing you to grip them fairly hard. Sans stumbles and makes a strangled sound, somewhere between a gasp and a moan.   
“heh, you’ll have to do that a bit more once we get to the bedroom” 

You hum happily at this discovered sweet spot of his, as he starts walking the two of you to the bedroom. You feel a bulge against your core, and feel a zap of arousal go straight from your belly to your clit. Oh god he actually has a dick, you had thought about lips but never even questioned whether he had other assets. It was hard and warm, hot even. You giggle to yourself as you think of calling it a ‘hot rod’, but immediately quiet when he gently sets you on the bed and grinds said ‘hot rod’ against you. A loud moan escapes you and he chuckles. “ive been wanting to hear you make these noises for a long time” You can’t help but blush at that, imagining him thinking about you is both embarrassing and hot. With it comes a rush of adrenaline, and you gently push him back. Before he can respond or say anything, you’ve grabbed the edges of your shirt and pulled it up and over your head, leaving you bare except your bra.

For a second Sans is completely still, his eyelights roaming your bare torso. You push back the urge to cover up, he was about to see much more of you and it wouldn’t do to become shy now. His eyes take on a gentler look behind the lust there, and he just whispers the word “beautiful”. He slowly pushes you back onto the bed, leaning in for another series of heated kisses. He leans his face down to start kissing your collar bone, while you reach up to start pushing his jacket off. Sans, apparently feeling a bit impatient, shrugs his jacket off with ease and immediately pulls his shirt over his head as well. You lean back to take in the sight before you. Sans is absolutely beautiful, the low light of the moon is gently fading in from behind the blinds of the window, giving him an ethereal look. His off white bones seem to gleam in the dark, and you can see gentle blue magic glowing from behind his ribs.

All you can do is whisper “Sans” reverently. He blushes a bit, but leans down again to place a kiss on the center of your chest, bringing his hands up to hover over your breasts. “may i?” he asks gently. Your arch your back to where your breasts touch his hands and he gasps. You moan a bit as you say “Yes, please” He wastes no time, reaching under your bra with one hand to play with your right nipple, and using the other to unhook the clasp on the back. You help him get your straps off, and he tosses the bra across the room. His hands immediately go for your chest again, gently squeezing one breast and playing with the nipple of the other. While his hands are otherwise occupied, you take the chance to test out his weak point again. Your hand goes for his ribcage, and you wrap your fingers around one of the ribs, gently rubbing it with your thumb. His eyes close and he moans out “oh shit that feels good”. You grin and lean your face towards the other side of his ribs, and take a long, slow lick on the closest one. He grunts and thrusts his covered bulge into you again. His eyelights are tiny white pinpricks in his sockets as he looks at you. You can only describe the look as pure hunger.

His hands go to the waistband of your pants, then slowly start pulling them off, giving you some time to stop him if you so choose. You can’t help but think how sweet that gesture is, but at the same time you have a wet heat you’d like him to take care of. You help him get your pants off and he lowers his face down, towards your center. He shudders as he gets close to you, kissing your thighs, first the left, then the right. His hands massage your calves as his face gets tantalizingly closer with each kiss. A moan escapes your mouth as he moves up to kiss your lower belly, you’re starting to get impatient as he dances around exactly where you want him. “Sans.. please” you grunt out. His smirk gets ever wider, and he finally lowers himself and licks up your slit, hitting your clit at the end. You moan out a quick “Ah!” as he does so, before he goes back and licks again. Your legs come up to rest on his shoulders, pulling him a bit closer as he laps at your clit. 

Your legs start trembling a bit as he slowly inserts one of his phalanges into you, curling it just right. “Oh god Sans that’s so good, right there” you moan out. You look down at him and the look on his face is just downright sinful. He swaps his tongue out for his thumb, gently caressing your nub and plunging his tongue deep into you at the same time. He closes his eyes as he thrusts his tongue in and out of you, and your toes curl as he lets out a deep growl. “fuck you taste nice” he manages to rumble out, as he pulls his face away from your lower half. You bite your lip as he sets your legs down. Your legs come back up slightly as you place your toes where the top of his shorts are, trying to shimmy them down with your feet. He laughs as he says “well aren’t you just -dripping- with anticipation”. You would have laughed were the look on his face not so predatory.

He helps you pull his shorts the rest of the way down, then leans back over you and places his forehead on yours. You glance down at his glowing blue cock, subconsciously licking your lips at the sight. He was nice and long, not too girthy. Excited to get to the main event, you lift your hips up a bit towards him and he chuckles. “you ready baby?” He asks. The new nickname sends another wave of arousal through you, and you furiously nod as he positions himself right at your entrance. With a groan from both of you, he pushes just the head in at first. Gently and slowly he thrusts in and out, going farther in with each thrust. Sweat beads on his forehead as his eyelights become impossibly bright. Finally, he is in full hilt. Panting hard, he pulls all the way out, looks right in your eyes and slams back in. Your toes curl and you can barely hold in the loud scream you want to let out at the sensation. He makes another deep growling noise as he starts to thrust into you in earnest. He reaches up and gently pinches your left nipple, while he starts sucking on the right one. 

You moan loudly at the change of pace, he removes his hand and mouth from your breasts and starts grabbing at your ass for leverage, lifting your lower back slightly up off the bed. “holy shit youre so tight” he whispers. He reaches down with his right hand and uses his thumb to slowly circle your clit. You pant and squeal a bit at the new intense sensation, rocking your hips in time with his. He leans down and kisses you hard, tangling his tongue with yours. You can taste yourself on him, and the taste of his mouth mixed with your own taste is incredibly erotic. You moan into his mouth and grasp the back of his head, scratching gently with your nails. As you part, he rests his forehead on your chest and you think you hear a whispered “fuck”. The pace you’re going at isn’t quite enough for you, and in a brief flash of confidence you pull his head towards yours and moan out “Fuck me, Sans”

A near animalistic sound comes from him at that statement, and he starts pounding into you, still swirling his thumb on your clit. The lewd slapping sound coming from the two of you spurs him on further, and a near constant growl is escaping him, the blue glow in his chest getting brighter with each thrust.

You whimper and lift one leg over his shoulder, allowing him to go much deeper into you. Taking the hint, he lifts your other leg and puts both over his shoulders, angling himself down. A scream rips its way out of your throat as he hits your g spot at this angle. The noise eggs him on, causing him to speed up and pound into you much harder. He leans forward and starts licking around your neck, thrusting into you with everything he’s got. “FUCK Sans.. I’m gonna..” You pant out, unable to really form a sentence through the bliss. He is still pounding into you, but small grunts and groans start to make their way out of his mouth and you can tell he is close too. With a few hard thrusts he leans forward, and bites into your shoulder HARD. The beautiful pain mixed with pleasure hits you all at once, and you come with a loud scream. He comes at the same time, tightening his jaw as he lets out just about the sexiest noises you’ve ever heard. 

Panting, he slowly pulls out of you and rolls over to the side, letting your legs fall down onto the bed. He puts his arm around your middle and holds you close. “oh my stars. that was amazing. you are amazing” he pants out. You giggle and run your finger up and down his ribs, causing him to shiver. “Well, you are simply -sans-ational” you reply. He barks out a laugh, and pulls you closer to him. His bones are warm, and soon, you find yourself drifting off into a blissful sleep.


End file.
